SE191482C1 - Razor blade and procedure for its manufacture - Google Patents

Abstract

The cutting edge of a safety razor blade is coated with a solid fluorocarbon polymer as defined. The coating is baked. The blade may be made of hardened carbon or stainless steel, other metals or metal alloys. The fluorocarbon polymers, which are solid polymers containing a plurality of (-CF2-CF2-) groups with or without terminal carboxyl groups, hydrogen and chlorine atoms, e.g. P.T.F.E., may be applied by sublimation, electrophoresis from charged liquid dispersions thereof, dipping in a dispersion of the particulate fluorocarbon polymer in a volatile liquid or spraying or brushing such dispersions. The volatile liquid may be water, dichlorodifluoromethane, dichlorotetrafluoroethane, trichlorotrifluoroethane and mixtures thereof. In the examples, steel blades are washed and dried and then coated by one of the above methods. If a dispersion is used then the volatile liquid is evaporated before carrying out the baking step. The baking step may be carried out simultaneously with the depositing step.ALSO:A dispersion of solid fluorocarbon polymer, as defined, p contains as dispersing agent water, dichlorodifluoromethane, dichlorotetrafluoroethane, trichlorotrifluoroethane or mixtures thereof. The fluorocarbon polymer contains a plurality of (-CF2-CF2-) groups with or without terminal carboxyl groups, hydrogen and chlorine atoms, e.g. P.T.F.E. The dispersion is used to coat razor blades.

Description

KLASS INTERNATIONELLSVENSK B 26 b69:21/02 PATENT- OCH REGISTRERINGSVERKET Ans. 12 678/11160 inkom den 30/12 1960 utlagd den 27/1 1964 THE GILLETTE Co., BOSTON, MASS., USA Rakblad jamte fiirfarande for dess framstallning Upp finnare • I W Fisebbein Prioritet begard (ran den 31 december 1959 (USA) Foreliggande uppfinning avser rakblad med en eller tvh. eggar och avser sdrskilt ett rakblad, som Sr forbattrat genom att dess skaregg Sr forsedd med en vidhaftande belaggning, som innehaller ett fluorkolvate, vilket forbattrar bladets rakningsformaga. Uppfinningen avser dessutom ett forfarande for framstallning av sadana rakblad. CLASS INTERNATIONAL SWEDISH B 26 b69: 21/02 PATENT AND REGISTRATION AGENCY Ans. 12 678/11160 was received on 30/12 1960 published on 27/1 1964 THE GILLETTE Co., BOSTON, MASS., USA Razor blades for its production Inventors • IW Fisebbein Priority requested (rob on 31 December 1959 (USA) Existing The invention further relates to razor blades having one or two edges, and more particularly to a razor blade which is improved by having its cutting edge provided with an adhesive coating containing a fluorocarbon which improves the shaving ability of the blade.The invention further relates to a method of making such razor blades.

Brukliga stalrakblad, p0. vilka foreliggande uppfinning kan fillampas, ha en tjocklek av 0,075 till 0,375 mm och uppvisa kilformiga skareggar, vilkas vinkel, som inn:esluter materiakt, Sr storre fin 14° och mindre an 35°. Fasetterna eller sidorna av en del sadana skareggar stracka: sig, raknat frail framkanten och bakat, over en stracka av 2,5 mm och mer. Varje eggsida bestar icke nadvandigtvis av en enda oavbrutet forlapande plan fasett utan kan besta av tva eller fler fasetter, vilka astadkommits genom successiv slipning eller hening och vilka skara varandra langs zoner, som vanligen aro parallella till den egentliga eggkanten. Den sista fasetten, dvs. den fa-sett, som gransar omedelbart intill den egentliga eggkanten, kan ha en bredd, som i j amforelse med diameter. av ett skaggstra, vilken i genomsnitt uppgar till ungefar 0,10,125 mm, Sr ringa och uppgar till ungefar 0,0075 mm, medan tjockleken av den egentliga eggkanten sjalv vanligen Sr mindre an 0,6 /2 och foretradesvis mindre an 0,/L. Rakbladet framstalles antingen av kolstal eller av hardbart rostfritt sthl. I hada fallen hardas bladet genom en lamplig varmebehandling. Den grad, i vilken bladet kan upphettas efterat, Sr begransad, eftersom en upprepad, alai& kraftig upphettning leder till en hardhetsforlust. Sasom Oman regel galler, att de hardade metallbladeggarna icke fa utsattas far inverkan av en temperatur over 205° C langre an fern minuter, enar eljest &Wet an-lopes och blir mjukt, varfor vid en typ av Dupl. kl. 22 g: 7/01; 69: 25; 75 c: 5/01 fluorkolvate granser aro satta for mien och sattet av behandlingen. Belaggningen kan emellertid Sven piforas blad, vilkas skaregg bortsett frail sta.' eller rostfritt sta.]. besta. av andra metaller eller metallegeringar eller aro belagda med dessa, varvid den hogsta ternperatur, f6r vilken dessa andra metaller eller metallegeringar kunna utsattas utan namnyard andring av de fysikaliska egenskaperna, sasom bekant kan ligga mom ett brett intervall. &Isom bekant kunna de brukliga stalrakbladen trots sin skarpa endast anvandas under smartor och obehag for rakning av ett torrt skagg, Tad& i allmanhet ett skagguppmj ukningsmedel, exempelvis vatten och/cller en rakkram eller raktval maste anvandas. Obehaget och den vid torrakning fororsakade smartan, beror ph den alltfOr stora kraft, som erfordras for att draga bladets skaregg genom de icke uppmjukade skaggstrana, varvid derma kraft overfores till de nerver i huden, som ligga i narheten av de harsackar, ur vilka skaggstrana uttrada; sasom bekant kan den smarta, som astadkommes genom alltfor kraftig dragning i dessa stran, fortsatta ytterligare tamligen lange, sedan dragningen upphort. Usual steel razor blades, p0. which the present invention can be filampased, have a thickness of 0.075 to 0.375 mm and have wedge-shaped cuttings, the angle of which encloses the material, is greater than 14 ° and less than 35 °. The facets or sides of some such cut edges stretch: themselves, shaved frail front edge and baked, over a stretch of 2.5 mm and more. Each edge of the edge does not necessarily consist of a single continuous flat facet, but may consist of two or more facets, which are formed by successive grinding or honing and which intersect along zones which are usually parallel to the actual edge of the edge. The last facet, ie. the fa-set, which examines immediately next to the actual edge of the edge, may have a width, as in comparison with diameter. of a skaggstra, which on average amounts to about 0,10,125 mm, Sr small and amounts to about 0,0075 mm, while the thickness of the actual edge itself itself is usually less than 0.6 / 2 and preferably less than 0, / L . The razor blade is made of either carbon steel or hardenable stainless steel. In this case, the blade hardens through a suitable heat treatment. The degree to which the blade can be heated afterwards, Sr limited, because a repeated, alai & vigorous heating leads to a loss of hardness. As Oman's rule states, the hardened metal blade edges must not be exposed to the effects of a temperature above 205 ° C for more than four minutes, otherwise unites & Wet anneals and becomes soft, which is why with a type of Dupl. at 22 g: 7/01; 69:25; 75 c: 5/01 fluorocarbon granules are set for the mine and set by the treatment. The coating can, however, Sven pifora's leaves, whose cuttings apart frail sta. ' or stainless steel.]. best. of other metals or metal alloys or are coated therewith, the highest temperature to which these other metals or metal alloys may be exposed without name change of the physical properties, as is known, may be within a wide range. & As is well known, the usual steel razor blades, despite their sharpness, can only be used during pain and discomfort for shaving a dry shag, Tad & in general a shaving softener, for example water and / or a shaving frame or shaving choice must be used. The discomfort and the pain caused by dry shaving is due to the excessive force required to pull the blade's scarlet edge through the unsoftened shaggy strands, this force being transmitted to the nerves in the skin near the hair follicles from which the shaving strands emerge. ; As is well known, the smartness which is achieved by excessive pulling in these strands can continue for quite some time after the pulling has ceased.

Forsok ha visserligen icke saknats att uppna en underlattning av rakningen och sSrskilt en minskning av denna dragning, icke endast genom en forbehandling av skaggstra.- na utan Sven genom pafiiring av belaggning7 ar av olika slag ph. bladet; de vid rakblad kanda belaggningarna medfora emellertid icke flagon namnvfird forbattring av rakbladets skaregenskaper. Belaggningar pa rakblad ha Sven tjanat andra andamal, sasom hojning av rostbestandigheten, bestfimning av bladets hrukstillstand, etc. Man kanner belaggningar av flytande, sarskilt oljeartade, material, tval, vax, kamfer, mjukningsme- 2— — delshaltiga plaster, sasom cellulosaderivat, grafit, alruminiumoxid, nickel, rodium, etc. Icke nagot av dessa belaggningsmaterial ha givit samma resultat som uppfinningen. Sfirskilt vid anvandning av grafit sasom belaggningsmaterial har man. utgatt fran att det uppvisar en mycket lag friktionskoefficient; mot forvantningarna ha emellertid fors& med belaggningar av_ grafit och andia ovan namnda material av mjukare och friktionsfriare natur visat, att de ge en. i jamforelse med belaggningen enligt uppfinningen endast ovasentlig eller joke nagon forbattring ails gentemot belaggningsfria blad. Attempts have certainly not been lacking to achieve a facilitation of shaving and in particular a reduction of this attraction, not only through a pre-treatment of the shavings, but Sven through the application of coatings of various kinds. the magazine; However, the coatings known on razor blades do not lead to a significant improvement in the cutting properties of the razor blade. Coatings on razor blades have served other purposes, such as raising the rust resistance, determining the leaf's crush condition, etc. Coatings of liquid, especially oily, materials, soap, wax, camphor, plasticizers, such as cellulose derivatives, graphite are known. , alumina, nickel, rhodium, etc. None of these coating materials have given the same results as the invention. Especially when using graphite as a coating material. assumed that it has a very low coefficient of friction; against the expectations, however, rapid coatings of graphite and other materials mentioned above of a softer and frictionless nature have shown that they give a. in comparison with the coating according to the invention only insignificant or joke any improvement ails towards coating-free leaves.

Dot är kant, att det aven redan foreslagits att pafora skareggen en vidhaftande belaggfling av ett organiskt gel av kiseltyp, som är polymeriserat i overhettad anga. Gentemot delta forslag, att utga fran en sadan grundsubstans for belaggningen, som ãr forhallandevis mjuk (gelartad), utmarker sig uppfinningen, enligt vilken man anvander belaggningsforeningar av fasta fluorkolvatepolymerer, vilka sasom bekant aro harda och sega, bl. a. av en forenkling av framstallningssattet genom att polymerisationsbetingelserna firo mindre kritiska. The downside is that it has also already been proposed to impose on the cutting edge an adherent coating of an organic gel of the silicon type, which is polymerized in superheated steam. In contrast to other proposals, to start from such a basic substance for the coating, which is relatively soft (gel-like), the invention stands out, according to which coating compounds of solid fluorocarbon polymers are used, which are known to be hard and tough, e.g. a. of a simplification of the production process by making the polymerization conditions less critical.

Uppfinningen avser ett rakblad med sardraget, att det uppvisar en till en skaregg vidhaftande belaggning av fasta fluorkolvatepolymerer, vilka innehalla en kedja av kolatomer med ett antal (—CF2—CF2—)-grupper. The invention relates to a razor blade with the feature that it has a coating of solid fluorocarbon polymers which adheres to a cutting edge, which contain a chain of carbon atoms with a number of (-CF2-CF2-) groups.

Ett rakblad med en sadan skareggsbelfiggping i form av en fast fluorkolvatepolymer har helt overraskande en anmarkningsvart langre kvardrOjande, hOgre rakningsformaga an alla hittills kanda rakblad med skareggsbelfiggning. Denna forbattring gor sig bemarkt genom en minskning av dragningen, dvs. genom en minskning av den for avskarning av skaggstrana erforderliga kraften, varigenom rakningen sker lattare och behagligare, sa att om sa. Onskas den fore rakningen sedvanliga uppmjukningen av skagget kan avkortas, eftersom uppmjukningen av skagget liar icke fir av sadan betydelse som vid anvandning av vanliga rakblad. Bladen enligt uppfinningen ha vid undersokning under omsorgsfullt kontrollerade betingelser avskarning av med vatten uppmjukade stran erfordrat mycket mindre kraft an samma blad utan belaggning. Denna minskning av dragningen kan besta under flera pa varandra foljande rakningar men varar icke obegransat. A razor blade with such a skareggsbelfiggping in the form of a solid fluorocarbon polymer has, quite surprisingly, a remarkably longer lingering, higher shaving shape than all hitherto known razor blades with skareggsbelfiggning. This improvement is noticeable through a reduction in the pull, ie. by a reduction of the force required for cutting the shaggy strands, whereby the shaving is easier and more comfortable, said that if said. If desired, the usual softening of the beard can be shortened, since the softening of the beard is not of such importance as when using ordinary razor blades. The blades according to the invention, when examined under carefully controlled conditions, cut off water-softened strands required much less force than the same blade without coating. This reduction in traction can last for several consecutive shaves but does not last indefinitely.

Belaggningar av fluorkolvaten och aven av sadana med ovan angiven struktur pa olika foremal, aven av metalliskt slag, aro redan. kanda. Man "[Inv emellertid harvid endast utnyttjat den lagre friktionskoefficienten, varmebestandigheten och egenskapen av dessa fluorkolvaten att icke Tara vidhaftande for att exempelvis sakerstalla, att mat icke fast branner vid koksredskap, far att vid sagar for klibbiga eller med klibbiga amnen impregnerade massor ininska fastklibbning av klibbigt *span pa tandernas och sagbladets sidoytor, f Or att mom bageritekniken bear-beta klibbigt sockerhaltigt material utan risk for fastklibbning vid arbetsredskapet, f Or att vid medicinska nalar underlatta instickandet i linden, for att belagga skalpeller, sa att icke nagot fasthaftar vid dessa, etc. mom bagerivasendet ha av fluorkolvatematerial helt bestaende, dvs. icke belagda knivar med rak eller rund egg anvfints for fordelning av sockermassa, deg eller andra klibbiga material. icke: mom nagot av forutnamnda anvandningsomraden är det fraga cm en forbattring av skaregenskaperna. Alla dessa kanda anvandningsoinraden skilja sig folj aktligen principiellt fan uppfinningen, som avser ett helt annat och egenartat problem, namligen att genom skarning avkorta en i endast en ande inspand tradbildning av den. typ, som ett skaggstra utgor och pa grund harav ger dessa kanda anvandningsformer joke lackmannen nagon ledning for losning av uppfinningsproblemet. Fackmannen kunde joke heller utlasa nagot ur de allmanna hfinvisningarna Over friktion hos och smorjning av fasta material i en larobok, som innehaller uppgifter om friktionskoefficienterna av olika icke metalliska substanser, hi. a. grafit och polymerforeningar av typen fluorkolvate, polyeten, polystyren, etc. Sasom redan angivits ovan, ha de jamforande forsOken med liknande substanser betraffande deras f Ormaga att forbattra ett rakblads rakningsegenskaper visat, att det icke foreligger nagra som heist synbara sammanhang mellan friktionskoeffieient och rakningsegenskaper. Dail& kunde fackmannen joke heller hamta nagon hanvisning ur de allmanna 151.0135ckerna, om att ett rakblad med den ovan angivna typen av belaggning av fluorkolvaten har extremt gynnsamma rakningsegenskap er. Coatings of the fluorocarbons and also of those with the above structure on various objects, also of metallic kind, are already in place. kanda. However, only the lower coefficient of friction, the heat resistance and the property of these fluorocarbons have been used. sticky * span on the side surfaces of the teeth and saw blade, f Or that mom bakery technology bear-beta sticky sugary material without risk of sticking to the work tool, f Or that in medical needles facilitate insertion into the linden, to coat scalps, so that nothing sticks to them , etc. If the bakery is made of fluorocarbon material completely existing, ie uncoated knives with straight or round edges are used for the distribution of sugar mass, dough or other sticky materials. Not: If any of the aforementioned areas of use, it is a question of an improvement of the cutting properties. these kanda usesoinraden differ folj actual actually pri ncipially fan the invention, which relates to a completely different and peculiar problem, namely to shorten, by cutting, a formation formed in it in only one spirit. type, as a skaggstra constitutes and on the basis of these, these known forms of use joke the painter gives some guidance for solving the problem of the invention. The person skilled in the art could also read something from the general instructions on friction in and lubrication of solid materials in a laro book, which contains information on the coefficients of friction of various non-metallic substances, hi. a. Graphite and polymer compounds of the fluorocarbon, polyethylene, polystyrene, etc. type As already stated above, the comparative experiments with similar substances concerning their ability to improve the shaving properties of a razor blade have shown that there is no apparent correlation between coefficient of friction and shaving properties. Dail & could the expert joke also get some male reference from the general 151.0135cker, that a razor blade with the above type of coating of the fluorocarbons has extremely favorable shaving properties.

Fluorkolvatebelaggningen eller -tiverdraget kan stracka sig fran den egentliga skareggen och bakat Over hela den kilformiga ytan och annu langre eller endast tacka den i anslutning till den egentliga skareggen befintliga delen av slutfasetten. Belaggningens exakta tjocklek är synbarligen icke kritisk och en tunnare kontinuerligt fOrlopande, vidhaftande belaggning med en tjocklek av samma storleksordning, som ett skikt av orienterade molekyler, har visat sig effektiv for andamalet enligt fOreliggande uppfinning. Belaggningen behaver icke ha en en likformig tjoeklek Over hela sin. utstrackning. The fluorocarbon coating or stripping can extend from the actual cutting edge and bake over the entire wedge-shaped surface and even longer or only thank the part of the final facet adjacent to the actual cutting edge. The exact thickness of the coating is apparently not critical and a thinner continuous, adherent coating of a thickness of the same order of magnitude as a layer of oriented molecules has been found to be effective for the spirit of the present invention. The coating does not need to have a uniform thickness throughout. extent.

De fluorkolvatematerial, som kunna anvandas enligt uppfinningen, utgora fasta amnen och omfatta olika fasta polymerer av tetrafluoreten, som innehalla en kedja av kolatomer med ett antal (—CF2—CF2—)- — —3 grupper. Dessa polymerers molekylvikt kan I den form, i vilken de paforas skareggen, ligga mom ett intervall fran 2000 och t. o. m. annu mindre upp till 2000000 och darover. Aven med polytetrafluoreten med mycket h8g molekylvikt i icke nedbruten form uppnas fordelar, nar de anvandas sasom belaggning pa rakblad av kolstal, aven om resultaten icke aro fullt sa tillfredsstallande, eftersom detta belaggningsmaterial lampar sig battre for blad, vilka framstallts av andra metaller eller metallegeringar. Andgrupperna i kolkedjorna kunna dessutom variera ph i och 'Br sig kfint satt, allt efter det vid framstallningen av polymeren anvanda forfarandet. Polymerer, som franastallts i vattenhaltiga medier uppvisa karboxiandgrupper, medan vid andra polymerer vate och/eller kloratomer aro bundna vid andkolatomerna i kedj an. The fluorocarbon materials which can be used according to the invention constitute solid substances and comprise various solid polymers of tetrafluoroethylene, which contain a chain of carbon atoms with a number of (-CF2-CF2 -) - - —3 groups. The molecular weight of these polymers, in the form in which they are pafora, can range from 2000 to even less than 2,000,000 and above. Even with very high molecular weight polytetrafluoroethylene in non-degraded form, advantages are obtained when used as a coating on razor blades of carbon steel, although the results are not so satisfactory, since this coating material is better suited for blades made of other metals or metal alloys. The duct groups in the carbon chains can also vary in pH and size, depending on the process used in the preparation of the polymer. Polymers prepared in aqueous media have carboxyand groups, while in other polymers vate and / or chlorine atoms are attached to the duck carbon atoms in the chain.

Vid anvandning av fluorkolvaten med hog molekylvikt paliires materialet pa bladets skaregg fOretradesvis pa sit salt, att skareggen placeras i narheten av ett forra.d av fluorkolvate, medan detta upphettas, varvid en belaggning av nedbrutet fluorkolvate utfalles pa skareggen genom sublimering. Elektrofores kan aven anvandas for utfallning ay ett material med hog molekylvikt ur laddade flytande dispersioner eller ocksa kan skareggen helt enkelt doppas ner i dispersionen och darefter lamnas att torka. When using the high molecular weight fluorocarbon, the material on the blade's cutting edge is preferably ground on its salt, that the cutting edge is placed near a supply of fluorocarbon, while this is heated, whereby a coating of degraded fluorocarbon is precipitated on the cutting edge by sublimation. Electrophoresis can also be used for precipitation of a high molecular weight material from charged liquid dispersions or the cutting edge can simply be dipped into the dispersion and then left to dry.

Fasta fluorkolvaten med forhallandevis lag molekylvikt kunna likaledes phforas skareggen pa sit salt, att denna neddoppas i en dispersion av det speciella fluorkolvatet, i ett flyktigt flytande medium eller att dispersionen sprutas pa skareggen eller palores med en pensel, varefter det flytande mediet avdunstas. Flyktiga, flytande anvandbara medier utgora hi. a. vatten och under handelsnamnet Freoner kanda foreningar, sasom diklordifluormetan, diklortetrafluoretan, triklortrifluoretan och deras blandningar. Solid fluorocarbons of relatively low molecular weight can likewise be formed into the salt on the salt, which is immersed in a dispersion of the special fluorocarbon, in a volatile liquid medium or that the dispersion is sprayed on the scar or palores with a brush, after which the liquid medium is evaporated. Volatile, liquid usable media constitute hi. a. water and under the tradename Freoner kanda compounds, such as dichlorodifluoromethane, dichlorotetrafluoroethane, trichlorotrifluoroethane and their mixtures.

Oberoende av det satt, pa vilket det fasta fluorkolvatet pafores skareggen, ma.ste bladet med det paforda fasta fluorkolvatet hardas vid en forhOjd temperatur am ungefar 90400° C, under en sa ling tidrymd, att fluorkolvatet blir fast vidhaftande vid underlaget. Mycket hogmolekyldra fluorkolvaten maste upphettas nastan till temperaturintervallets ovre grans, medan forhallandevis lagmolekylara fluorkolvaten icke erfordra sit hoga tem- peraturer. Tiden kan variera fran mindre an 2 minuter och upp till 48 timmar och &rover alit efter det anvanda speciella fluorkolvatet, underlagets art, hastigheten, med vilken det belagda bladet upphettas, och den uppnadda temperaturen. Stalblad fa icke upphettas langre an fern minuter vid en temperatur av hogst ungefar 205° C, sh att bladen, sasom redan namnts, icke skola anl5pas eller mjukna. Vid blad av vissa andra material, spe- ciellt av rostfritt stal, kan en begransad mjulming eller anlopning av bladen eftersom de darmed forbundna olagenheterna mer an val uppvagas av den forbattrade rakningseffekten, som astadkommes enligt uppfinningen. I allmanhet maste stalbladen upphettas minst N minuter vid 150-160° C, for att man skall erhalla de basta resultaten, aven om en langre tids uppvarmning icke skadar belaggningen. I nagra fall fir det att upphetta bladet fore eller under paforingen av det fasta fluorkolvatet, varigenom hardningen genomf Ores samtidigt med paforingen. Regardless of the manner in which the solid fluorocarbon is applied to the cutting edge, the blade with the predetermined solid fluorocarbon must be cured at an elevated temperature of about 90400 ° C, for such a period of time that the fluorocarbon becomes firmly adhered to the substrate. High-molecular-weight fluorocarbons must be heated almost to the upper limit of the temperature range, while relatively low-molecular-weight fluorocarbons do not require their high temperatures. The time can vary from less than 2 minutes and up to 48 hours depending on the particular fluorocarbon used, the nature of the substrate, the rate at which the coated sheet is heated, and the temperature reached. Stable leaves should not be heated for more than four minutes at a temperature of at most 205 ° C, so that the leaves, as already mentioned, should not be touched or softened. In the case of blades of certain other materials, in particular stainless steel, a limited grinding or tarnishing of the blades, since the associated impurities can more than possibly be offset by the improved shaving effect achieved according to the invention. In general, the steel blades must be heated for at least N minutes at 150-160 ° C in order to obtain the best results, even if a prolonged heating does not damage the coating. In some cases it is possible to heat the blade before or during the application of the solid fluorocarbon, whereby the curing is carried out at the same time as the application.

Aven om sasom redan namnts belaggningen pa skareggen av bladet, som ar fardigt att tagas i bruk, ar utomordentligt tunn, ar det for framstallningen av en sadan belaggning, onskvart att belaggningen vid hardningens pabOrjande ar avsevart tjockare. Alit det ph skareggen kvarvarande overflodiga materialet, som vid hardningen icke bindes vid underlaget foreligger i form av en los film, som latt kan avlagsnas genom borstning eller gnidning. Det ar emellertid joke vasentligt att avlagsna detta overskottsmaterial fore bladets anvandning. Although, as already mentioned, the coating on the cutting edge of the blade, which is ready for use, is extraordinarily thin, for the production of such a coating, it is desirable that the coating at the beginning of the hardening is considerably thicker. All the excess material remaining in the pH scar, which does not bond to the substrate during curing, is in the form of a loose film which can be easily removed by brushing or rubbing. However, it is important to remove this excess material before using the blade.

Da det icke exakt gar att utrona det sktt pa vilket bildningen av belaggningen forsiggar, antages, utan att detta begransar uppfinningen, att en koalescens av minst nagra fasta fluorkolvatepartiklar sker och att en iimsesidig inverkan sker mellan fluorkolvatet och den underliggande ytan, exempelvis sta.- let, varvid en kraftig bindning astadkommes mellan fluorkolvatet och underlaget. Den resulterande tunna vidhaftande belaggningen, som mekaniskt bares upp i hela sin utstrackning av det underliggande bladet, minskar dragningen under rakningen och gOr att rakningen sker lattare och behagligare. Since it is not possible to ascertain exactly the nature of the formation of the coating, it is assumed, without limiting the invention, that a coalescence of at least some solid fluorocarbon particles occurs and that a mutual effect occurs between the fluorocarbon and the underlying surface, e.g. thereby creating a strong bond between the fluorocarbon and the substrate. The resulting thin adhesive coating, which was mechanically carried up throughout its extent by the underlying blade, reduces the pull during shaving and makes shaving easier and more comfortable.

Uppfinningen itskitdliggOres narmare me-deist foljande exempel. Det bar visat sig, att alla de behandlade bladen vid verkliga rakningsprov ha anmarkningsvart forbattrade rakningsegenskaper i jamfOrelse med samma slags blad, som icke behandials enligt uppfinningen. The invention is further illustrated by the following examples. It was found that all the treated leaves in actual shaving tests have remarkably improved shaving properties in comparison with the same kind of blades which are not treated according to the invention.

Exempel 1. 500 mg fast tetrafluoretenpolymer (i form av stycken, skurna ur en under handelsnamnet Teflon kand folic) fylldes ph ett med rostfritt stal fodrat keramikr5r (det rostfria stalskiktets tjocklek var 0,75 mm; keramikrorets langd var 50,8 mm, dess diameter 11,11 mm och dess vaggtjocklek 1,6 mm) Keramikroret upphettades genom att en. elektrisk strom bringades att passera genom en spiralformad volframtrad, med en tjocklek av 1 nun, vilken lindats omkring keramikroret med 30 vary per 50,8 mm. Ett rakblad av hardat kolstal med en tjocklek av 0,125 mm och som i forvag rengjorts genom tvattning med trikloretylen samt torkats, placerades med sin skfiregg mot den oppna 4— — anden av riiret pa ett avstand av 4- cm fran detta. Det hela placerades sedan i ett vakuumskap, som evakuerades till ett tryck av -4 mm Hg. Volframspolen upphettades darefter elektriskt, tills degeltemperaturen nadde 370 100° C. Strommen. reglerades sedan sa, att ett tryck av 3X-4 mm Hg upprattholls under upphettningen, vilken fortsattes fyra timmar. Bladet uttogs darefter och uppvisade ett utfallt skikt pa skareggen, vilket visade interferensfth-ger i ljusmikroskop. Bladet placerades sedan i en luftugn yid 160° C under 40 minuter. Example 1. 500 mg of solid tetrafluoroethylene polymer (in the form of pieces, cut from a trade name Teflon kand folic) was filled into a ceramic tube lined with stainless steel (the thickness of the stainless steel layer was 0.75 mm; the length of the ceramic tube was 50.8 mm, its diameter 11.11 mm and its cradle thickness 1.6 mm) The ceramic tube was heated by a. electric current was passed through a helical tungsten wire, with a thickness of 1 nun, which was wound around the ceramic tube with 30 vary per 50.8 mm. A razor blade of hardened carbon steel with a thickness of 0.125 mm and which has been pre-cleaned by washing with trichlorethylene and dried, was placed with its cutting edge against the open edge of the tube at a distance of 4 cm from it. The whole was then placed in a vacuum cabinet, which was evacuated to a pressure of -4 mm Hg. The tungsten coil was then electrically heated until the crucible temperature reached 370,100 ° C. was then regulated so that a pressure of 3X-4 mm Hg was maintained during the heating, which was continued for four hours. The blade was then removed and showed a precipitated layer on the cutting edge, which showed interference characteristics in the light microscope. The blade was then placed in an air oven at 160 ° C for 40 minutes.

Exempel 2. Ett rakblad av rostfritt stal, inkopt i Oppna marknaden, rengjordes omsorgsfullt genom tvattning med trikloretylen samt torkades. Dess skaregg neddoppades sedan i en kolloidal vattendispersion, innehallande 25 viktprocent finfordelad fast tetrafluoretenpolymer (Teflon Clear Finish, som forsaljes av E. I. DuPont de Nemours and Co., Inc., Wilmington, Delaware, A.f.s.). Vid uttagning ur dispersionen befann sig pa bladets skaregg en belaggning av vattendispersionen, som torkades en timme yid ungefar 50° C i luften, varefter belaggningen hardades sju minuter vid 400° C. Example 2. A stainless steel razor blade, purchased at the Open Market, was thoroughly cleaned by washing with trichlorethylene and dried. Its cutting edge was then immersed in a colloidal aqueous dispersion containing 25% by weight of finely divided solid tetrafluoroethylene polymer (Teflon Clear Finish, sold by E. I. DuPont de Nemours and Co., Inc., Wilmington, Delaware, A.f.s.). When removed from the dispersion, a coating of the aqueous dispersion was present on the blade edge, which was dried for one hour at about 50 ° C in air, after which the coating was cured for seven minutes at 400 ° C.

Exempel 3. En finfordelad fast fluorkolvatepolymer, som inneholl en kedja av kolatomer med ett antal (--CF2—CF2—)-grupper och aven ett mindre antal (ungefar 1 viktprocent) kloratomer och ett lika stort antal vateatomer samt bade ett smaltintervall av 265-295° C (Fluorowax TLT-17, Lot No. 2, flan den i exempel 2 angivna amerikanska firman) dispergerades i en bland-mug av Freon 12 (diklordifluormetan.) och Freon 114 (diklortetrafluoretan) i viktforhallandet 40:60, varvid en dispersion bildades, som innehOoll 1 viktprocent torrsubstans. Derma dispersion sprutades ur en tryekbehallare pa skareggen av ett rakblad av i exempel 1 beskrivet slag, vilket rakblad i forvag rengjorts pa i foregaende exempel beskrivet salt, varefter bladet hardades sju timmar i en luftugn vid en temperatur av 165° C. Example 3. A finely divided solid fluorocarbon polymer comprising a chain of carbon atoms having a number of (--CF2-CF2 -) groups and also a smaller number (about 1% by weight) of chlorine atoms and an equal number of hydrogen atoms and having a melting range of 265 -295 ° C (Fluorowax TLT-17, Lot No. 2, flan the American company listed in Example 2) was dispersed in a mixed mug of Freon 12 (dichlorodifluoromethane) and Freon 114 (dichlorotetrafluoroethane) in a weight ratio of 40:60, a dispersion was formed which contained 1% by weight of dry matter. This dispersion was sprayed from a pressure vessel onto the cutting edge of a razor blade of the type described in Example 1, which razor blade was pre-cleaned on salt described in the previous example, after which the blade was cured for seven hours in an air oven at a temperature of 165 ° C.

Exempel 4. Den i exempel 3 beskrivna fluorkolvatepolymeren dispergerades i Freon 113 (triklortrifluoretan) till en dispersion med en halt av 1 viktprocent torrsubstans. Skareggen pa ett rakblad av i exempel 1 beskrivet slag, vilket rakblad rengjorts pa ovan beskrivet satt, neddoppades i denna dispersion och fick sedan torka i luften. Bladet upphettades darefter 10 timmar vid 160° C. Liknande resultat erh8llos aven vid anvandning av liknande dispersioner med en. halt av upp till 11 viktprocent fluorkolvatepolymer. Example 4. The fluorocarbon polymer described in Example 3 was dispersed in Freon 113 (trichlorotrifluoroethane) to a dispersion with a content of 1% by weight of dry matter. The cutting edge of a razor blade of the type described in Example 1, which razor blade was cleaned in the manner described above, was immersed in this dispersion and then allowed to dry in the air. The blade was then heated for 10 hours at 160 ° C. Similar results were also obtained using similar dispersions with one. content of up to 11% by weight of fluorocarbon polymer.

Exempel 5. Det i exempel 3 beskrivna fasta fluorkolvatet pafordes skareggen pa ett rakblad ay i exempel 1 angivet slag pa i samma exempel beskrivet satt med undantag for att degeltemperaturen holls vid ungefar 165° C och att upphettningen fortsattes 10 minuter. Bladet uttogs sedan ur vakuumskapet och visade interferensfarger pa skareggen. Liknande resultat kunna erhallas genom upphettning yid sá lag temperatur som ungefar 120° C under langre tidrymd. De enligt ett av dessa satt belagda bladen placerades sedan i en luftugn och forvarades 15 minuter i denna vid en temperatur av 160° C. Liknande resultat erhollos nar uppvirmningen genomfordes under 16 timmar vid samma temperatur i luftugnen. Example 5. The solid fluorocarbon described in Example 3 was applied to the cutting edge on a razor blade as described in Example 1 in the same manner described in the same example except that the crucible temperature was maintained at about 165 ° C and that heating was continued for 10 minutes. The blade was then removed from the vacuum cabinet and showed interference colors on the cutting edge. Similar results can be obtained by heating at a temperature of about 120 ° C for a long time. The coated sheets according to one of these were then placed in an air oven and stored for 15 minutes in it at a temperature of 160 ° C. Similar results are obtained when the heating is carried out for 16 hours at the same temperature in the air oven.

Exempel 6. Det i exempel 1 beskrivna fasta fluorkolvatet upphettades I luft vid atmosfarstryck i en silikadegel till en temperatur av ungefar 2° G, tills en tjock vit rok kontinuerligt utvecklades ur degeln. Ett rakblad av i exempel 1 beskrivet slag, som rengjorts pa ovan beskrivet satt, h011s med sin egg i den vita riiken pa ett avstand av 75 mm fran degeln under 10 minuter. Pa grand av degelns narhet antog bladet en temperatur av ungefar 150° G under utfallningen av fluorkolvatet pa bladets skaregg, varigenom en ytterligare hardning var ono-dig. Example 6. The solid fluorocarbonate described in Example 1 was heated in air at atmospheric pressure in a silica crucible to a temperature of about 2 ° C, until a thick white smoke continuously developed from the crucible. A razor blade of the type described in Example 1, cleaned in the manner described above, is held with its edge in the white rim at a distance of 75 mm from the crucible for 10 minutes. Due to the proximity of the crucible, the blade assumed a temperature of about 150 ° C during the precipitation of the fluorocarbon on the cutting edge of the blade, whereby a further hardening was unnecessary.

Claims (12)

Patentansprik:Patent claim: 1. Rakblad, kanneteeknat av en vid en skaregg haftande belaggning av fasta fluorkolvatepolymerer, vilka innehalla en kolkedja med ett antal (—CF2—CF2—)-grupper.Razor blades, characterized by a coarse-grained coating of solid fluorocarbon polymers, which contain a carbon chain with a number of (-CF2-CF2-) groups. 2. Blad enligt patentanspraket 1, kannetecknat darav, att belaggningen bestar av en fast tetrafluoretenpolymer.Blade according to claim 1, characterized in that the coating consists of a solid tetrafluoroethylene polymer. 3. Blad enligt patentanspraket 1 eller 2, kannetecknat darav, att polymeren uppvisar andp-upper, vilka utgoras av karboxigrupper, vateatomer och kloratomer.Blade according to claim 1 or 2, characterized in that the polymer has andp-upper, which consist of carboxy groups, hydrogen atoms and chlorine atoms. 4. Blad enligt nagot av patentanspraken 1-3, kannetecknat darav, att rakbladet är framstallt av hardat stal.Blade according to one of claims 1 to 3, characterized in that the razor blade is made of hardened steel. 5. Blad enligt nagot av patentanspraken 1-4, kannetecknat darav, att rakbladet ãr framstallt av rostfritt stal.Blade according to any one of patent claims 1-4, characterized in that the razor blade is made of stainless steel. 6. Forfarande for framstallning av ett rakblad enligt nagot av patentanspraken 1-5, kannetecknat darav, att det fasta fluorkolvatet paliires en hardad skaregg av bladet och att det upphettas under betingelser, vid vilka icke nagon alltfor stor forlust sker av bladets hardhet och varvid en vidhaftande belaggning bildas pa eggen.6. A method of making a razor blade according to any one of claims 1-5, characterized in that the solid fluorocarbon is ground to a hardened cutting edge of the blade and that it is heated under conditions in which no excessive loss is made of the hardness of the blade and wherein a adhesive coating is formed on the edge. 7. Forfarande enligt patentanspraket 6, kannetecknat darav, att en dispersion ay enskilda partiklar av det fasta fluorkolvatet i en flyktig vatska pafores bladet, varefter vatskan avdunstas.7. A method according to claim 6, characterized in that a dispersion of individual particles of the solid fluorocarbon in a volatile liquid is pafores the sheet, after which the liquid is evaporated. 8. Forfarande enligt patentanspraket 7, kannetecknat darav, att den anvanda flyktiga vatskan utgores ay vatten.8. A method according to claim 7, characterized in that the volatile liquid used is water. 9. Forfarande enligt patentanspraket 7, ka.nnetecknat darav, att den anvanda flyk- — — tiga vatskan utgores av diklordifluormetan, diklortetrafluoretan, triklortrifluoretan eller deras blandningar.9. A process according to claim 7, characterized in that the volatile liquid used is dichlorodifluoromethane, dichlorotetrafluoroethane, trichlorotrifluoroethane or their mixtures. 10. F8rfarande enligt patentanspraket 6, kannetecknat darav, att fluorkolvatet pal& res skareggen ph sa salt, att denna Mlles I angor av fluorkolvatet.10. A method according to claim 6, characterized in that the fluorocarbon is polished to the edge of the salt so that it is affected by the fluorocarbon. 11. Forfarande enligt nagot av patentanspraken 6-10, kannetecknat darav, att upphettningen utfores under minst 30 minuter vid en temperatur av 150-160° C.A method according to any one of claims 6-10, characterized in that the heating is carried out for at least 30 minutes at a temperature of 150-160 ° C. 12. Forfarande enligt nagot av patentan spraken 6-11, kannetecknat darav, att upphettningen och paforingen av belaggningen utforas samtidigt. Anforda publikationer: Patentskrifter !ran USA 2 855 669.12. A method according to any one of claims 6-11, characterized in that the heating and pafing of the coating is carried out simultaneously. Request Publications: U.S. Patent Nos. 2,855,669.